On Thursday 11 March 2010 20:09:34 James Bottomley wrote: > On Thu, 2010-03-11 at 09:28 -0500, Theodore Tso wrote: > > On Mar 11, 2010, at 8:57 AM, Nikanth Karthikesan wrote: > > > I guess, what he meant was, to keep filesystem blocks aligned, even if > > > the partition is not. Say if the partition is mis-aligned by 512-bytes, > > > let the filesystem waste 4k-512bytes and keep it's blocks aligned. But > > > it might be a case of over-engineering, possibly requiring disk format > > > change. > > > > Ah, yes, I agree with you; that's probably what he meant. > > > > Sure, that's theoretically possible, but it would mean changing every > > single filesystem, and it would require a file system format change > > --- or at least a file system format extension. > > > > It would seem to be way easier to simply fix the partitioning tools to > > do the right thing, though. > > Actually, it's a layering violation. The filesystem shouldn't need to > probe the device layout ... particularly when there are complexities > like is it logical 512 or physical, and if logical 512 on 4k does it > have an offset exponent or not. > > We can transmit certain abstractions of information up the stack (like > stripe width for RAID arrays which should be the fs optimal write size), > but for this type of alignment, which can be completely solved at the > partition layer, the information should really stay there and the > filesystem should "just work". > Right. It would be layering violation and we have LVM to solve it already. The real problem, here is just that partitioning-tools should create partitions that can work with both XP as well as Windows7. May be distro installers, should ask the user which compatibility he needs. Thanks Nikanth -- To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
